80 Amp Alt enough?

[Mugen 10+ year member]

Is 80 amps enough for a a little over 1000w on a sub and about 200-300w on mids? I just looked my alt up on that rockauto.com site and it's showing an 80 amp alt in an '05 Pontiac Vibes (my next system is going to be in that).

I really don't want to spend $200+ on a new alt. Will anything bad happen if my speakers try to draw more power than it can supply (like seriously ****ing it up)?

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[n2audio 5,000+ posts]

I really don't want to spend $200+ on a new alt. Will anything bad happen if my speakers try to draw more power than it can supply (like seriously ****ing it up)?

Nothing tragic will happen. No. I would expect to see some pretty good dimming at high volumes, but how big of a problem that is, is for you to decide.

Worst case scenario is that slowly your battery will be weakened, and one morning it just won't have the current to crank the engine.

For that to happen you'd have to be slamming every time you get in the car. 1500w at 1/2 max output playing average music doesn't require much current. Blasting bass-heavy stuff is where the high current draw is at.

Regardless - 1500w is a lot of power for an electrical system that size, and if you don't use some common sense I'd say you COULD have some issues.

The RIGHT thing to do would be upgrade the alt, but you don't need to go to 200A. Something as reasonable as 110A would make a huge difference.

If you stay with the 80A, just make it a point to turn the system way down a few minutes before you turn the engine off. That will give the alt some time to top-up the battery before it sits overnight.

FWIW - I ran about 1000w rms in my car on an OLD 75A alt. It had about 180k on it when I did the initial install. It worked well enough for a couple years. At 226k it finally gave up. Put in a 110A and have had no problems since -- 271K now.

 

[questionaire 10+ year member]

Nothing tragic will happen. No. I would expect to see some pretty good dimming at high volumes, but how big of a problem that is, is for you to decide.
Worst case scenario is that slowly your battery will be weakened, and one morning it just won't have the current to crank the engine.

For that to happen you'd have to be slamming every time you get in the car. 1500w at 1/2 max output playing average music doesn't require much current. Blasting bass-heavy stuff is where the high current draw is at.

Regardless - 1500w is a lot of power for an electrical system that size, and if you don't use some common sense I'd say you COULD have some issues.

The RIGHT thing to do would be upgrade the alt, but you don't need to go to 200A. Something as reasonable as 110A would make a huge difference.

If you stay with the 80A, just make it a point to turn the system way down a few minutes before you turn the engine off. That will give the alt some time to top-up the battery before it sits overnight.

FWIW - I ran about 1000w rms in my car on an OLD 75A alt. It had about 180k on it when I did the initial install. It worked well enough for a couple years. At 226k it finally gave up. Put in a 110A and have had no problems since -- 271K now.

Would 1600@1 ohm have problems on stock 130A??

 

[Mugen 10+ year member]

Where can I find pricing on a new alt, just to check it out. If it's reasonable, I can probably stretch it, but I'm still going to wait to get all my stuff in first and see how bad it is. And I listen to mostly rap/hip-hop stuff, so it'd be pretty much bass bass bass all the time.

Any links to an "alternator store" or something >_>

 

[dennisthamenace 10+ year member]

Would 1600@1 ohm have problems on stock 130A??

i have a 120 alt on my infiniti and running around 1600-1700@1ohm, you will see significant dimming at high volumes, i can tell you that much.

 

[dleccord 5,000+ posts]

Would 1600@1 ohm have problems on stock 130A??

its fine. that's how much i run and i have very little dimming at full tilt.

 

[bikinpunk 10+ year member]

One thing to consider is what else the alternator is powering. I have an 06 Civic, and am running a 1000/1 (1000 w rms) & another 200w rms for my doors. The stock alty is 90 amps. I have dimming at full volume, but not severe. The Civic has LED brakes & taillights. I know that LED's require much less power than conventional bulbs, so I'm assuming that has something to do with my low amp alternator not being stressed badly. I could be wrong, but it's just a thought.

 

[Mugen 10+ year member]

Hmm, is an alternator something I could do myself or would I need to pay someone to do that? I may just get something other than an Fi Q, because I don't feel like tacking $250-$300 on top of the system I already had planned out. Maybe I'll just get two Assassin 12"s like I originally planned...

Two Assassins would take only 700w at max output, so that shouldn't be too bad. What is the max voltage/wattage of an 80amp alt?

 

[Mat Dope 10+ year member]

well my 80a could barley run 700rms without dimming so i definatly would stay under 1000rms unless you plan on upgrading the alt.

 

[pitbull12888]

Hmm, is an alternator something I could do myself or would I need to pay someone to do that? I may just get something other than an Fi Q, because I don't feel like tacking $250-$300 on top of the system I already had planned out. Maybe I'll just get two Assassin 12"s like I originally planned...
Two Assassins would take only 700w at max output, so that shouldn't be too bad. What is the max voltage/wattage of an 80amp alt?

You can do it yourself.. all you do is switch the wires from the old to the new, which should be about 3-4 wires

 

[Mugen 10+ year member]

You can do it yourself.. all you do is switch the wires from the old to the new

Yes, but wouldn't I need to take the old one out? Where is your alt at? What's it look like? Is it in an easy place to get too?

 

[SUB_URBAN 10+ year member]

im running 1500 on 105 alt, and if i burp it with the lights on we have some crazy dimmage.

 

[SUB_URBAN 10+ year member]

Yes, but wouldn't I need to take the old one out? Where is your alt at? What's it look like? Is it in an easy place to get too?

It usually is easy to get to and it is just removing a couple of bolts and placing the new one in the same spot and bolting back up.

 

[questionaire 10+ year member]

its fine. that's how much i run and i have very little dimming at full tilt.

If bass boost an gain was close to flat would that help? Would I notice torque, horse power etc decrease using stock an this amp??

 

[Mugen 10+ year member]

If bass boost an gain was close to flat would that help? Would I notice torque, horse power etc decrease using stock an this amp??

You really shouldn't use bass boost anyway, but if you set your gains so that the maximum the subs every draw RMS is 1600w, then they'll never go over 1600w. You could lower the gains, but then your sub wouldn't be as loud. I got some help at genvibe.com and I think I'm gonna order a 170a Alternator, that should last me for quite some time. Hopefully I won't need a new battery with it though //content.invisioncic.com/y282845/emoticons/blackeye.gif.66a1670f5aaf7f406e783a63e3387dc5.gif